Good answers…Bond usually explains that stirring bruises the cocktail, which while technically true is not correct as distinguishing from shaking. Bruising is the act of water melting into a cocktail and diluting it. Bruising is a natural part of any cocktail and both shaking and stirring succeed in bruising a drink. Bond implies that the presence of a foreign object, the spoon, does more than shake. But shaking requires a shorter duration to receive comparable amounts of melting. That said, shaking also is more violent and is more likely to produce ice shards in the drink. This is not desirable in a spirits-only cocktail like a Martini.